Microfluidic chip having increased throughput for use in a system for delivery of a payload into a cell

Abstract

Provided is a microfluidic chip for causing the delivery of a payload to a cell comprising a first layer, a second layer, and a fluid flow region between the first layer and the second layer. This microfluidic chip is configured to accept flow of a cell suspension into the fluid flow region. The first layer of the microfluidic chip comprises a protrusion extending toward the second layer to form a constriction between the protrusion and the second layer, wherein the constriction is configured to cause perturbation of a cell membrane of a cell of the cell suspension as the cell passes through the constriction.

1 . A microfluidic chip for causing the delivery of a payload to a cell, the chip comprising:
 a first layer;   a second layer; and   a fluid flow region between the first layer and the second layer, wherein the chip is configured to accept flow of a cell suspension into the fluid flow region, the cell suspension comprising a plurality of cells,   the first layer comprises a protrusion extending toward the second layer to form a constriction between the protrusion and the second layer, wherein the constriction is configured to cause perturbation of a cell membrane of a cell of the plurality of cells as the cell passes through the constriction.   
     
     
         2 . The microfluidic chip of  claim 1 , wherein the first layer comprises silicon. 
     
     
         3 . The microfluidic chip of  claim 1 , wherein the second layer comprises glass. 
     
     
         4 . The microfluidic chip of  claim 1 , wherein the protrusion extends away from an inner surface of the first layer in a height direction perpendicular to the inner surface of the first layer and comprises a proximal end that is adjacent to the inner surface of the first layer. 
     
     
         5 . The microfluidic chip of  claim 1 , wherein the protrusion extends away from an inner surface of the first layer in a height direction perpendicular to the inner surface of the first layer and comprises a distal end of the protrusion that forms the constriction between the distal end of the protrusion and an inner surface of the second layer, wherein a height of the constriction between the distal end of the protrusion and the inner surface of the second layer, as measured in the height direction, is less than or equal to 5 microns. 
     
     
         6 . The microfluidic chip of  claim 5 , wherein the height of the constriction is less than a diameter of the cell of the plurality of cells. 
     
     
         7 . The microfluidic chip of  claim 1 , wherein the microfluidic chip comprises an inlet and an outlet, wherein the inlet is positioned at a first end of the chip and the outlet is positioned at a second end of the chip opposite the first end, wherein a distance between the inlet and the outlet extends in a direction perpendicular to an inner surface of the first layer. 
     
     
         8 . The microfluidic chip of  claim 4 , wherein the proximal end of the protrusion has a thickness extending perpendicular to the height direction and extending from an upstream side of the protrusion to a downstream side of the protrusion, wherein the thickness of the proximal end of the protrusion is greater than or equal to 10 microns. 
     
     
         9 . The microfluidic chip of  claim 5 , wherein the distal end of the protrusion has a thickness extending perpendicular to the height direction and extending from an upstream side of the constriction to a downstream side of the constriction, wherein the thickness of the distal end of the protrusion is greater than or equal to 5 microns. 
     
     
         10 . The microfluidic chip of  claim 4 , wherein the protrusion has a length extending perpendicular to the height direction and extending along an interface between an upstream side of the constriction and a downstream side of the constriction, wherein the length is greater than or equal to 0.5 cm. 
     
     
         11 . The microfluidic chip of  claim 10 , wherein the interface between the upstream side of the constriction and the downstream side of the constriction that comprises one or more of a curve and an angle. 
     
     
         12 . The microfluidic chip of  claim 1 , wherein the interface between the upstream side of the constriction and the downstream side of the constriction forms a serpentine path. 
     
     
         13 . The microfluidic chip of  claims 12 , wherein the serpentine path of the interface is perpendicular to the height direction at all locations along the serpentine path. 
     
     
         14 . The microfluidic chip of  claim 12 , wherein the serpentine path comprises one or more right angles. 
     
     
         15 . The microfluidic chip of  claim 1 , wherein a first dimension of the microfluidic chip extending perpendicular to a height direction that is perpendicular to a planar surface of one or both of the first and second layers is 18-24 mm. 
     
     
         16 . The microfluidic chip of  claim 1 , wherein a second dimension of the microfluidic chip extending perpendicular to a height direction that is perpendicular to a planar surface of one or both of the first and second layers is 8-15 mm. 
     
     
         17 . The microfluidic chip of  claim 1 , wherein a height dimension of the microfluidic chip extending in a height direction that is perpendicular to a planar surface of one or both of the first and second layers is 1000-1500 microns. 
     
     
         18 . The microfluidic chip of  claim 1 , wherein the second layer contacts the first layer at a plurality of support pillars, wherein each support pillar of the plurality of support pillars extends from an inner surface of the first layer to the second layer. 
     
     
         19 . The microfluidic chip of  claim 1 , wherein the first layer has a total height of 500-750 microns as measured in a height direction that is perpendicular to a planar surface of the first layer. 
     
     
         20 . The microfluidic chip of  claim 1 , wherein the first layer has a minimum height of 450-650 microns, wherein the minimum thickness is measured in a height direction that is perpendicular to an inner surface of the first layer and wherein the minimum thickness is measured from an outer surface of the first layer to a nearest inner surface of the first layer that interfaces with the fluid flow region. 
     
     
         21 . The microfluidic chip of  claim 1 , wherein the second layer has a thickness of 450-800 microns as measured in a height direction that is perpendicular to a planar surface of one or both of the first and second layers. 
     
     
         22 . The microfluidic chip of  claim 1 , wherein an uppermost surface of the protrusion comprises a planar surface parallel to an inner surface of the first layer and perpendicular to a height direction in which the protrusion extends from the inner surface of the first layer. 
     
     
         23 . The microfluidic chip of  claim 1 , wherein an uppermost surface of the protrusion comprises a planar surface parallel to an inner surface of the second layer and perpendicular to a height direction in which the protrusion extends from the inner surface of the first layer. 
     
     
         24 . The microfluidic chip of  claim 1 , wherein a side surface of the protrusion extends upwards from an inner surface of the first layer at an angle. 
     
     
         25 . The microfluidic chip of  claim 24 , wherein the side surface of the protrusion is angled at 50-60 degrees from the inner surface of the first layer. 
     
     
         26 . The microfluidic chip of  claim 24 , wherein the side surface of the protrusion is angled at 54.7 degrees from the inner surface of the first layer. 
     
     
         27 . The microfluidic chip of  claim 1 , wherein the cell suspension comprises a payload. 
     
     
         28 . The microfluidic chip of  claim 1 , wherein the chip is configured to operate at a pressure of greater than or equal to 10 psi. 
     
     
         29 . The microfluidic chip of  claim 1 , wherein a quotient of a cross-sectional area of the constriction to a perimeter of the constriction is greater than or equal to 0.5 microns. 
     
     
         30 . A method of causing the delivery of a payload to a cell, the method comprising:
 receiving flow of a cell suspension into a fluid flow region of a microfluidic chip, the cell suspension comprising a plurality of cells;   perturbing a cell membrane of a cell of the plurality of cells by causing the cell to flow through a constriction formed between a protrusion and a second layer of the microfluidic chip, the protrusion extending from an inner surface of a first layer of the microfluidic chip toward the second layer of the microfluidic chip, wherein the perturbation of the cell membrane allows entry of a payload into the cell.   
     
     
         31 . The method of  claim 30 , wherein perturbing a cell membrane of a cell of the plurality of cells by causing the cell to flow through a constriction formed between a protrusion and a second layer of the microfluidic chip comprises causing the cell to flow through the constriction at a flow rate of greater than or equal to 0.5 m/sec. 
     
     
         32 . The method of  claim 30 , wherein the microfluidic chip is configured to operate at a pressure of greater than or equal to 10 psi. 
     
     
         33 . The method of  claim 30 , wherein the cell suspension comprises the payload. 
     
     
         34 . The method of  claim 30 , comprising causing the payload to come into contact with the cell suspension following perturbation of the cell membrane. 
     
     
         35 . A method of fabricating a microfluidic chip for causing the delivery of a payload to a cell, the method comprising:
 etching into a first layer to form a recessed surface of the first layer and a protrusion of the first layer; and   affixing a second layer to the first layer to form a microfluidic chip having a fluid flow region defined between the recessed surface and the second layer and a constriction defined between the protrusion and the second layer.   
     
     
         36 . The method of  claim 35 , wherein etching into a first layer to form a recessed surface of the first layer and a protrusion of the first layer comprises using wet or dry chemical etchants. 
     
     
         37 . The method of  claim 35 , wherein etching into a first layer to form a recessed surface of the first layer and a protrusion of the first layer comprises etching into the first layer to a depth of greater than or equal to  30  microns to define the fluid flow region. 
     
     
         38 . The method of  claim 35 , wherein etching into a first layer to form a recessed surface of the first layer and a protrusion of the first layer comprises etching into the first layer to a depth of less than or equal to 5 microns to form a distal end of the protrusion. 
     
     
         39 . The method of  claim 35 , wherein etching into a first layer to form a recessed surface of the first layer and a protrusion of the first layer comprises etching into the first layer to form a distal end of the protrusion, wherein the distal end of the protrusion has a thickness that extends perpendicular to a height direction that is perpendicular to a planar surface of the first layer, wherein the thickness of the distal end extends from an upstream side of the protrusion to a downstream side of the protrusion, wherein the thickness of the distal end of the protrusion is greater than or equal to 5 microns. 
     
     
         40 . The method of  claim 35 , wherein the protrusion has a length extending perpendicular to the height direction and extending along an interface between an upstream side of the constriction and a downstream side of the constriction, wherein the length is greater than or equal to 0.5 cm. 
     
     
         41 . The method of  claim 40 , wherein the interface between the upstream side of the constriction and the downstream side of the constriction that comprises one or more of a curve and an angle. 
     
     
         42 . The method of  claim 40 , wherein the interface between the upstream side of the constriction and the downstream side of the constriction forms a serpentine path. 
     
     
         43 . The method of  claim 42 , wherein the serpentine path of the interface is perpendicular to the height direction at all locations along the serpentine path. 
     
     
         44 . The method of  claim 42 , wherein the serpentine path comprises one or more right angles.